Electric compensator



Aug. 27, 1946.

Original Filed Oct. 12, 1939 L. BATCHELDER I ELECTRIC GOMPENSATOR '2 Sheets-Sheet l T T T 1 4;

X0 4; LI fiH 4/2 29 INVENTOR.

ATTORNEY Patented Aug. 27, 1946 ELECTRIC COMPENSATOR Laurence Batchelder, Cambridge, Mass., assignor to Submarine Signal Company, Boston, Mass, a corporation of Maine Original application ctobe1:12, 1939, Serial No.

299,180, now abandoned. Divided and this application December 5, 1940, Serial No. 368,656

3 Claims. 1

The'present application is a division of my copending application Serial No. 299,180, filed October 12, 1939, now abandoned.

The present invention relates to electric compensators particularly to such as are used for the determination of the direction of submarine sound sources. For this purpose a plurality of electroacoustic transducers for producing electrical response upon excitation by compressional waves are mounted at spaced positions in a predetermined configuration. A wave impulse arriving from a distant source will, therefore, strike the several transducers or receivers at different instants of time whereby the electrical currents or voltages produced by the said devices will vary in time phase depending upon the angle which the direction of the sound source makes with the surface upon which the receivers are mounted. By progressively varying the phases of the several electric impulses so produced in such a manner as to bring them all into phase, the direction of the sound source can be determined by noting the amount of phase variation required. For'this purpose adjustable electrical retardation lines are commonly employed. These are frequently divided into two parts, the binaural or B-line and the maximum lines. The present invention relates particularly to a maximum-line switch.

The invention will best be understood with reference to the accompanying drawings in which Fig. l is a schematic diagram of an electric compensator in accordance with the present invention, and Fig. 2 is a development of one of the maximum line switches in accordance with the present invention.

Referring to Fig. 1, four compressional wave receiving devices I are shown. These all have one lead connected to a common conductor 2. The other terminals of the left pair of receivers are connected to the input of the left maximum line 3 at 4 and 5, while the right pair of receivers is connected to the input of the right maximum line 6 at I and 8. The lines 3 and 6 are electric retardation lines of recurrent sections formed of inductances 9 in series and capacitances I 0 in shunt as heretofore used in the art. The ends of the lines are terminated by additional capacitors as shown to provide perfect midshunt termination. The junction of the series inductances are connected to contact studs II of the maximum line switches each of which includes a pair of movable brushes I2, I3 and I4, I5, respectively. These are connected to the terminals of the center tapped auto transformers I 6 and I1, respectively. The auto transformers are center tapped inductances having mutual inductance between the two parts of their windings, as provided, for example, by common iron cores as shown.

The center taps I8 and I9 lead respectively to the inputs of the transformers 28 and 29, the transformer secondaries being connected across the binaural or B-line as shown. The output of the B-line is connected to the telephone indicators 36 and 3?. The B-line switch, here shown schematically, is more fully described in my prior United States Patents Nos. 2,070,570 and 2,088,580.

It will now be understood that compressional wave energy striking the receiving devices I will cause them to produce electrical currents having a phase difference depending upon the time of arrival of the sound energy at the several receivers. The maximum lines by means of the switches make it possible to bring the energy from the individual units of the two groups of receivers into phase. The energy from the two groups of receivers is then impressed upon the B-line. The energy from the left group of receivers passes through the left portion of the B-line while that from the right group of receivers passes through the right portion of the B-line.

The maximum line switches comprising the brushes I2 and I3 and the auto transformer I6 for the left line as seen in Fig. 1 and the brushes I4, I5 and auto transformer I! for the right line make possible substantially perfect midseries terminations for both parts of each of the maximum lines without the necessity of providing center taps in the series inductances of the lines. One of these switches is shown in greater detail in the development present in Fig. 2. A portion of the retardation line comprising the inductances 9 and the capacitances I 0 is shown for six different positions of the brushes. The contact studs I I connected to the terminals of the inductances 9 and the two movable brushes I2 and I3 which are connected to the terminals of the auto transformer I6 having the center tap l8 are shown in their true relative sizes and spaces which they must have in order that the transitions be equally spaced.

To this end it is necessary that the transitions of each brush from one stud to the next be instantaneous and that the transitions be equally spaced as the brushes move along the studs. If we let the width of the studs be represented by S, the width of the brushes by b, and the pitch of the stud by P, the transitions will be instantaneous if b=P s (1) In practice it is not essential that the brushes themselves be made of exactly the correct width but they can be made wider than the required value and bevelled at their edges. In order to make the transitions equally spaced, it is evident from Fig. 2 that where B is the total span of the two brushes. Hence From Equations 1 and 3 it follows that the transitions will be equally spaced if The progressive position of the brushes as they are advanced over the studs is shown in Fig. 2. In position lboth brushes l2 and H! are in contact with a single stud so that the lead 18 is effectively directly connected tothe line at the junction of two series elements. Both ends of the line are thereby terminated in a mid-shunt manner.

In position 2 both the brushes have advanced to the right with the brush l3 in a transition position between one stud and the next. 'In position 3 the brush I3 has completed contact with the next stud while the brush I2 is still in contact with the preceding stud. The auto transformer I6 is thereby shunted across one of the inductances 9. The center tap l8 is therefore effectively connected to the center of the element 9 whereby both ends of the line are terminated in a mid-series manner. In position 4, the brushes have moved a further increment to the right, while in position the brush I2 is in the transition position. In position 6 both brushes l2 and. I3 are in contact with the next stud and 4 both ends of the line are again terminated in a mid-shunt manner as in position 1.

Having now described my invention, I claim:

1. In an electric compensator having an electric retardation line formed of a plurality of recurrentsections of inductive series elements and capacitive shunt elements, means for effectively connecting to the electrical center of one of said inductive elements comprising a center-tapped auto transformer and means for connecting the same in parallel with said inductance element.

'2. In an electric compensator having an electric retardationline formed of a plurality of recurrent sections of inductive series elements and capacitive shunt elements, an auto transformer having a center, tap and two terminals and switch means 'for progressively connecting said terminals to the extremities of one of said inductances, then both terminals to the junction between the latter inductance and next adjacent inductance, then to the extremities of the lastmentioned inductance and so on.

3. In an electric compensator having an electric retardation line formed of a plurality of recurrent sections of inductive series elements and capacitive shunt elements, a switch mechanism including first contact members connected between adjacent series elements, an auto transformer having a center-tapped Winding, a pai of second contact members one connected to each extremity of said transformer, means mounting both first and second contact members in cooperative relation to each other and so arranged that the space between adjacent first contact members is the eifective width of each of the second contact members and the total span of the two second contact members less the width of one of them is one half the distance between corresponding edges of adjacent first contact members, and means for moving the second contact members relatively to the first.

LAURENCE BATCHELDER. 

